On $(j,k)$-symmetrical functions

Piotr Liczberski; Jerzy Połubiński

Displaying similar documents to “On $(j, k)$ -symmetrical functions”

$Σ$ -isomorphic algebraic structures

Ivan Chajda, Petr Emanovský (1995)

Mathematica Bohemica

Similarity:

For an algebraic structure $= (A, F, R)$ or type and a set $Σ$ of open formulas of the first order language $L ()$ we introduce the concept of $Σ$ -closed subsets of . The set $ℂ_{Σ} ()$ of all $Σ$ -closed subsets forms a complete lattice. Algebraic structures , of type are called $Σ$ -isomorphic if $ℂ_{Σ} () ≅ ℂ_{Σ} ()$ . Examples of such $Σ$ -closed subsets are e.g. subalgebras of an algebra, ideals of a ring, ideals of a lattice, convex subsets of an ordered or quasiordered set etc. We study $Σ$ -isomorphic algebraic structures in dependence...

Upper and lower solutions for singularly perturbed semilinear Neumann's problem

Róbert Vrábeľ (1997)

Mathematica Bohemica

Similarity:

The paper establishes sufficient conditions for the existence of solutions of Neumann’s problem for the differential equation $μ y " + k y = f (t, y)$ which tend to the solution of the reduced problem $k y = f (t, y)$ on $[0, 1]$ as $μ \to 0 .$

Linear integral equations in the space of regulated functions

Milan Tvrdý (1998)

Mathematica Bohemica

Similarity:

n this paper we investigate systems of linear integral equations in the space $𝔾_{L}^{n}$ of $n$ -vector valued functions which are regulated on the closed interval $[0, 1]$ (i.e. such that can have only discontinuities of the first kind in $[0, 1]$ ) and left-continuous in the corresponding open interval $(0, 1) .$ In particular, we are interested in systems of the form x(t) - A(t)x(0) - 01B(t,s)[d x(s)] = f(t), where $f \in 𝔾_{L}^{n}$ , the columns of the $n \times n$ -matrix valued function $A$ belong to $𝔾_{L}^{n}$ , the entries of $B (t, .)$ have a bounded variation...

Essential norms of a potential theoretic boundary integral operator in $L^{1}$

Josef Král, Dagmar Medková (1998)

Mathematica Bohemica

Similarity:

Let $G \subset ℝ^{m}$ $(m \geq 2)$ be an open set with a compact boundary $B$ and let $σ \geq 0$ be a finite measure on $B$ . Consider the space $L^{1} (σ)$ of all $σ$ -integrable functions on $B$ and, for each $f \in L^{1} (σ)$ , denote by $f σ$ the signed measure on $B$ arising by multiplying $σ$ by $f$ in the usual way. $𝒩_{σ} f$ denotes the weak normal derivative (w.r. to $G$ ) of the Newtonian (in case $m > 2$ ) or the logarithmic (in case $n = 2$ ) potential of $f σ$ , correspondingly. Sharp geometric estimates are obtained for the essential norms of the operator $𝒩_{σ} - α I$ (here $α \in ℝ$ ...

Displaying similar documents to “On ( j , k ) -symmetrical functions”

Σ -isomorphic algebraic structures

Upper and lower solutions for singularly perturbed semilinear Neumann's problem

Linear integral equations in the space of regulated functions

Essential norms of a potential theoretic boundary integral operator in L 1

Displaying similar documents to “On $(j, k)$ -symmetrical functions”

$Σ$ -isomorphic algebraic structures

Essential norms of a potential theoretic boundary integral operator in $L^{1}$